Minister for Foreign Affairs Charlie Flanagan said: "The Consular Section of my Department, in conjunction with our Embassy in London is monitoring the situation and we are not at this time aware of any Irish citizens affected."

"Anyone with concerns for family and friends can contact the Consular Division of my Department on 353 1 408 2000."

He added: "I am shocked and horrified by the large loss of life in Manchester last night and my thoughts and prayers are with those affected, and we stand by our nearest neighbour, the U.K. especially due to the strong links between our country and the city of Manchester."

Young sobbing girls wearing pink Ariana Grande t-shirts were seen clutching their parents outside the concert as armed police and helicopters rushed to the scene.

One witness reported being blown off his feet just after the lights came up at around 10.40pm, while others said they saw smoke and heard an explosion near the foyer area, before seeing people covered in blood.

There are unconfirmed reports that a number of people have suffered "shrapnel type injuries" in the incident at the 21,000-capacity arena, as hospitals reported they were expecting "mass casualties."

GMP Chief Constable Ian Hopkins held a press conference just before 3am on Tuesday, where he said that 19 people are confirmed dead and 50 others injured.

He confirmed it was being treated as a terrorist incident and said casualties are being treated at six hospitals across Greater Manchester.

Any Irish people with concerns for family and friends can contact the Department of Foreign Affairs on 353 1 408 2000.